Internal-combustion engine



Se t.

p 27 1927 H. 1 BRowNBAcK INTERNAL COMBUSTION ENGINE sept. 27, 1927.1,643,603

v H. L. BROWNBACK INTERNAL COMBUSTIQN ENGINE Filed Nov. 22, 1923 3Sheets-Sheet 2 nvenfoz Sept. 27,1927.

H. L. BROWNBACK INTERNAL coMBUsTIoN ENGINE Filed Nov. 22, 1923 3Sheets-Sheet. 3

@nvm/dov efl'ozne S.

Patented sept. 27, 1927.

UNITED ls'rfarlezfs,

1,643,603 PATE-NT OFFICE'.

HENRY LOWE BROWNBACK, or NoRRIsToWN, rENNsYLvANIA.'

Application 1ed Novemberi22', 1923.' Serial No. 676,463.

rThis invention is an improvement in 2- cycle internal combustionengines having one or more units, and the principal object of theinvention is to provide a novel 2- cycle engine each cylinder thereofbeing stepped, and housing a stepped differential piston, the upperorsmaller end of each cylinder being adapted to act as the firing,comprcssiornor working chamber; the space between the bottom of thepiston and lower end of the working cylinder being adapted to act as thepre-compression, suction, or charging chamber, and the space included inthe crankcase, below the piston being adapt-f ed to form the aircompression chamber, said pistons being connected to a connecting rod,scotch yoke, or other device adapted to convertthe reciprocating motionof the piston into rotary motion of the crank shaft.

Another objectof the invention is to provide a novel 2-cycle internalcombustion engine. provided with exhaust or escape valves or portsopening into the working chamber at or near the vlower end of theworking stroke of the piston; and provided with a valve, or valves, ofthe slide, poppet, rotary, or piston types, said valve or valves beingoperated automatically ortmechanically, to admit hydrocarbon vapor andair, or oxygen into the pre-compression chamber during the whole or apart of the working stroke of the pist-on; said engine being alsoprovided with a valve, or valves connecting the pre-compression chamberwith the working chamber during a part or the whole of the return strokeof the piston. v Y

A further object ofthe invention is to provide an internal combustionengine in which hydrocarbon vapors or gases, and air or oxygen arecompressed and burned above a piston, the waste or spent gases in theworking cylinder after ignitioin'escaping to the atmosphere through avalve or port at or near the end of the down or working y stroke of thepiston while new vapors ror gases, or vapors and gases mixed with oxygenor air, are being drawn or driven by atmespheric or mechanical pressureinto the remaining portion of such vapors beingv e-compression chamber,While during thev forced intothe aspirating pre-compression chamber ofone of the other units.

A still further object is to'provide a novel 2-.cycle internalcombustion engine in which an' is drawn or forced into the aircompression chamber o'n thel 11p-stroke of the piston', 'and iscompressed therein on the down stroke, andforced into the workingcylinder during a portion, or all of the duration of the escapement ofwaste or exhaust gases from the Working chamber, thereby scavenging andcooling said working chamber. y

In my' novel .9u-cycle internal combustion engine-the displaced volumeof gasesy contained in the pre-compression chamber is preferably inexcess of that in the work- Aing chamber, and is also at higherpressure;

and the air in the air compressing chamber is of greater displacedvolume than the volume of the working chamber; also the displacementofthe pre-compression chamber is greater than 'that of the working`chamber.

Other' minor objects ofthe inventionwill be hereinafter set forth.

Y I will explain the invention with reference to the accompanyingdrawings which illustrate one practical embodiment thereof to enableothers to adopt and use the same, and will summarize in'the'claims theessential features of the invention, the novel constructions, and novelcombinations of parts for which protection is desired.

In the'drawings':

Fig. l is a rfront elevation of my novel 2-cycle internal combustionengine. Y

Fig. Qyis a vertical longitudinal section through the engine.

Fig. 3 is a transverse section on the line 3 3 Fig. l, showing thepiston in the up position.

Fig. 4 is a section on the line l--t Fig. l` sho-wing the piston in thedown position.

Fig. 5 is a section on the line 5&5, Fig. l.

Fig.V 6 is an elevation of the main valveV of the engine.

Fig. 7 is a top plan View of said valve. Y

Fig. 8 is asection on the line 8-8, Fig. 6.

As shown in the drawings, vmy novel ,engine comprises a base casting l,adapted to house the crank shaft 2 of the engine, which y shaft ishoused in suitable bearings la in the casting. in the. usual manner. he'engine consists of one or more units, two units being shown in thedrawings and hence an intermediate partition 1b is provided Within thebase casting l, to separate the crank cases of said units, and theintermediate partition 1b is also provided with a bearing l adapted tohouse the crank shaft 2. The crank cases and their bearings Parepreferably made air-tight to prevent the escape of air from the ends ofthe casing, and to prevent the passage of air from one crank space tothe other past the intermediate partition 1b.

Each half of the Acasting l is provided with a cylinder bore lC adaptedto house the lower enlarged end of a hollow stepped or differentialpiston 8, as hereinafter set forth. Suitable water ducts 1d are formedaround the cylinders 1c for the purpose of cooling same.

On one end-of4 sha-ft 2 is mounted the fly wheel 2a, and on the otherend of the shaft 2, adjacent the opposite end of the cast-ing l, aremounted the timing gears 2b, 2, which drive the camshaft 4l, said gearsbeing preferably housed in a suitable housing le integral with thecasting l.V

Upon the casting l is mounted a cylinder casting 5 which is preferablydetachably attached to the casting l in the usual manner. Preferably agasket 5a is interposed between the castings l and 5 in order to make agas-tight connection therebetween. Casting 5 is provided with cylinderbores 5b, which cylinder bores are disposed Yin axial alignment with,but are 'smaller in diameter than said cylinder bores 1, cylinder boreslc and 5b thus forming stepped cylinders within the castings l and 5.Preferably, water ducts 5C are provided around the cylinders 5b for thepurpose of cooling said cylinders.

:In the bottom face of the casting 5, concentric with the cylinder bores5b are pro- .vided annular recesses 5d adapted to receive plates 5eprovided with bores 5f of the same diameter as the cylinder bores 5b.lln the bores 5f are provided the usual annular recesses to receivestui'ling rings 5g adapted to contact with the wall of the pistonc toprevent passage of vapors or air from cylinder 5b to the cylinder 1, andvice-versa. Y

Uponthe casting 5 is detachably attached a cylinder head 6, and betweencasting 5 and headft) is a gasket 6ZL in the usual manner. in the bottomface of head 6 are two semispherical chambers 6b concentric with theaxes of the cylinder bores 5b and le, said chambers 6b closing the topsof the cylinders 5b. Around the chambers 6b is a water duct 6C 'havingan inletV 6d, andwater ducts 6C communicate w'tn water ducts 5C incasting 5 by means of registering perforations in the said ductsat theirmeeting faces. EX- tending through the head 6 and into `each depression.6b are .sparleplugs .6e adapted to ignite the charge in the workingcylinders 5b. -Y

As shown in Fig. et eachA piston 3 is preferably hollow and is closed atits upper end 3, and the body of the piston comprises a tubular portion3b of suitable diameter to make aclose sliding fit in the cylinder bores5b, the upper end of said body portion 3b being provided with the usualpiston rings 3. rlhe upper end of each piston 8 is adaptn ed to litwithin a cylinder bore 5b, and the lower open end of the piston 3extends below the casting 5 and into the bores l of the base casting l,and the lower end of-said piston 3 is provided with an exteriorcircumferential flange 3d of diameter to suit the bore 1C, and the outerperiphery of flange 3d is provided with annular recesses for thereception of stuliing rings 3e to prevent passage of the air or vaporstherepast. Adjacent the top of the piston 3 is a hinge bar 3f upon whichis pivotally mounted the upper end of the connecting rod 3g, connectingsaid piston with the crank shaft 2.

Hence, the piston 3 and the cast-ings l, 5 and 6 form three chambers A,B, C, Fig. 4) the space above the piston 3 and within the bore 5b belowthehead 6 forming the firing, or working chamberv A of the engine; thespace exterior to the piston wall 3')` and within the bore lc andincluded between the casting 5e and the flange 8d of piston 3, formingthe fuel pre-compressing and suction or charging chamber B; and thecrank space, the interior of the piston 3, and the bore 1 of the castingl below the piston flange 3d, forming the air compression chamber C. Asthe piston reciprocates the respective capacities of the chambers il, B,and C are varied accordingly.

The fuel vapors or gases are admitted into the firing orworking-cylinder A through a port 5h in the side of each cylinder bore5b adjacent Ythe top thereof, which port 5h may be opened and closed bymeans of a suitablev valve 7, of any suitable type, suchas a slide,rotary, poppet, or piston valve, the particular valve 7 shown in thedrawings being a piston valve operating in a cylinder bore 5j in anextension 5k integral with the cylinder casting. Bore 5j is preferablyclosed at its top by means ofthe cylinder head G, and suitable waterducts may be provided around bore 5j as shown, said ducts being fed bymeans of registering perfor-ations in the adjacent meeting faces of saidparts 5k and 6. Portliconnnuni'cates, as shown, with the bore 5J', andthe lower end of bore 5j terminates in an outwardly extending passage 5madapted to be engaged by a manifold 8 to which is connected thecarburetor 9. TWithin the bore 5J' above the passage 5m but below port5h isan annular recess 5u, which is connected to and communicates with apipe or ductlO :leading from said annular recess 5v to the fuel ports10a at the'top of the `fuel pre-compression chamber B. i

Piston valve 7 asA shown in Figs. 6, 7 and 8 is preferably tubular, andis `'open at the top, but closed at the bottom by a plate 7 a. In thesideof the valve 7, above the base. plate 7 :1, are a plurality ofcirculnferentially disposed openings 7b communicating with the hollowinterior of the valve. f desired, suitable radially disposed vanes 7 Cmay be formed on the upper side of plate 7 a' to direct the fuel vapors,passing into openings 7b, toward the center ofthe valve. Piston rings 7dare preferably mounted on the wall of said piston valve, and also on thebase plate 7a, to prevent pas age of fuel vapors orge-.ses past thevalve 7 except through the interior thereof.' Y

Valve 7 is reciprocated in the bore 5j, to open and close port 5 and tobring the openings 7b of valve 7 in or out of register with the annularreces-s 5,, by lmeans of a rod 7 C entering` and housed in the lowerpart of casting 5k, which rod 7C is preferably tapped "into the baseplate 7 of valve 7.

Rod 7e may be reciprocatedby any suitable means. As shown, the lower endof rod 7e is slidably mounted in a bearing-lf on a cam-shaft housing 1g,the. lowerven'd of said rod 7e extending adjacent Vthe cam-shaft lf. Gnthe lower end of rod is a yoke Tf carrying rollers 7g adapted to engagea cam It@ mountedfon said cam-shaft t. Y As cam La is revolved the valve7 will'acc'ordingly be raised or lowered. i

Then valve 7 is raised, as 'in Fig. 3, the port 5h to the workingchamber A is closed by the sides of said valve, and the gases from thecarburetor 9 may pass from manifold 8 through passage 51, into theannular recess 5 and down into pipe l0, and from hence into thepre-compression'chamber-B, but the gases cannot pass upwardly throughvalve 7 and into chamber Athrough the ports 51". vVhen however valve 7isin lowered piston, as shown in Fig. t, the gases from chamber B maypass upwardly through' ports 10a and pipe lO, into annular recess 5a,through openings 7b in valve 7, up through valve 7 and through port 5hinto the working chamber A, but the gases cannot pass back into thevcarburetor 9 since plate 7a of valve 7 blocks the communication betweenannular recess 5 and passage 5m.

An exhaust port- 5 is located in the sideV of cylinder 5l at a pointacent the. lower limit of travel of the piston 3, as Ashown in Figs. 3and 4, said exhaust port 5 exhausting either into the atmosphere, orthrough an exhaust manifold binto a suitable mufier not shown).4"i/"rhenthe top, 3 of the piston 3 passes the port 5 the said portJwill be opened or closed depending on Awhether the piston isV movingdown or up.V Y

' Piston 3 is preferably hollow and is provided With an opening 3h inthe side thereof adjacent the top enda, said opening being adapted toregister with a U-shaped port 5 inthe side wall of the cylinder 5", theoutlet .of said 'port being preferably diametrically chamber Cy willvthen be compressed on the clown-stroke of thepiston 3, and when theopening 3h in the upper end of the piston l3 registers `with the port 5in the lower end of the cylinderlbore 5b, at the end of the workingstroke of the piston, thei compressed air in the chamber C will lrushout throu h port 5 into the'wor'king chamber A and thoroughly y scavengeand cool said working chamber forcing out all the waste. products ofcombustion from lsaid working chamber A. Valve 7 connecting vtheprefcompressor chamber BY with the working chamber A is never open atthe same time thatthe exhaust port 5.is open. K 1 I The mixture in thepre-compression chamber B is frich, and t-he mixing of the gasestherefrom' with the compressed excess air in the working cylinder Aforms the explosive mixture forA the engine. l l Y hfanifold, seeFigs. 4and 5 is preferably provided with an upwardly opening valve 8a at itsconnection of the carburetor 9', to prevent the back flow Ofhydr'oearbonvapors from the pre-compressor chamber B towards the workingA cylinderA, due to valve 7 closing before the piston 3 finishes its upstroke, andhence connecting duct l0 with-passage 5m before the finish of up'stroke. The gases Y thus forced back in to manifold 8 are trapped inmanifoldS and maybe led into the precompression chambersl B of the otheren! gine units which are aspirating at that time.4

Also, a duct Y(not shown) maybe 'formed inthe passage 10 between thepre-compres-- sor B and firingcylinder A, into 'which all of thecompressors may pump, said ductpreferably having a cubicalcapacity ofless than one compressor, and the gas from this 'duct may be lead intothe firing cylinder A during any portion of the up st-roke of the pistonafter the lclosing of the exhaust port 5. r` p Operation.

yThe operation of t'heengine'is as follows: VThe engine shown is voftheZ-clyele two unit type andthe cranks Aof the crank shaft are Vhenceangularly spaced o apart, hence one unit, or as many units may be addedthereto as desired without departing from the scope of the invention.

`With one of the cylinders as in Fig. 8, in the firing position itspiston is at its upper limit of travel and all valves are closed, valve6 being in its uppermost position closing the port h. As the piston isforced downward by explosion the fuel vapors are sucked through theports 5m, 5, l0 and lOfL into the aspirating pre-compression chamber Buntil the lower en-d of valve 6 has been lowered by the action of camshaft 4 to block the f passage from port 5m into duct 10. During CII thedown stroke of the piston 3 the air in the chamber C is being highlycompressed When the upper end of the piston 3 unseals the exhaust port 5near or at the end of the down stroke of the piston, the waste or burntgases will'be exhausted from the working cylinder into the atmosphere orcxhaust manifold 5P, while the port 5 is closed by the valve 7.

While t-he exhaust port 50 is still open the piston continues itsdown-stroke until the opening 3 in the upper side of the piston 3registers with the duct 5 in the cylinder wall 5b, at which time thecompressed air in the air compression chamber C is allowed to escapethrough the opening 3 and duct 5 into the working cylinder A oppositethe exhaust port 9, during the whole or a portion of the duration of theescapement of waste or exhaust gases from the working cylinder A`thereby thoroughly scavenging and cooling the working cylinder.

Upon the beginning of the upstroke, the duct 5 and exhaust port 5 areclosed by the piston 3, and air is sucked into the aircompressionchamber C through valve lh. Valve 6 then drops into lower positionclosing the passage between port z51 and duct 10, and allowing thecompressedl fuel vapors to be forced though duct 10, through the valve 7an'd through port 5, into the working cylinder A where it is mixed withthe compressed excess air in the working chamber which air has beencompressed by the upward movement of the piston 3.

The piston continues its upward movement, but before reaching the top ofits travel valve 7 closes, forcing the gases back into the passage 5mand manifold 8, but the valve 8a prevents the vapors from being forcedback` into the carburetor 9. The gases in the manifold 8 are then ledinto the aspirating pre-compression cylinders B of the other engineunits.

The piston then finishes its upward stroke, and the fuel vapors and airtherein are fully compressed, and ready for ignition at the beginning ofthe next working stroke.

What I claim is 1. For an internal combustion engine having a workingcylinder and having a fuel pre-compression cylinder; a valve casingclosed at bothjends; a port adjacent the lower end of the casingcommunicating with a carburetor; a port adjacent the upper end of saidcasing communicating withV said working cylinder; said casing having anannular recess in its walls intermediate said ports and communicatingwith said pre-compression cylinder; a tubular piston reciprocablymounted in said casing above said first mentioned port Vand having itslower end closed; said piston having openings in its walls adapted 'toregister with said annular recess; and means for shifting said valve toestablish communication between said lower port and annular recess, orbetween said upper port and annular recess.

2. F or amultiple unit internal combustion engine, each unit comprisinga working cylinder and a lfuel pre-compression cylinder; a valve foreach unit comprising a cylindrical casing closed at both ends; a port insaid casing adjacent its lower end communicatingwith a carburetor; aport in said casing adjacent the upper end of said casing communicatingwith said working cylinder; said casing having an annular recess in itswalls intermediate said ports and communicating with saidpre-compression cylinder; a tubular piston reciprocably mounted in saidcasing above said lirst port and having its lower end closed; and havingopenings in its walls adapted to register with said annular recess;radially disposed vanes within said piston for directing the vaporstowards the center of said piston; and a piston rod on said pistonactuated by said engine cam shaft for shifting said piston to establishcommunication between said lower port and annular recess, or betweensaid upper port and annular recess.

3. A multiple unit internal combustion engine, each unit comprising thecombination of a working cylinder, a fuel pre-compression cylinder, andan air compression cylinder all in axial alignment; a differentialpiston reciprocably mounted in each unit; means for admitting air intothe air compression cylinders on the return strokes; a valve for eachunit for admitting fuel vapors from a carburetor manifold into the fuelprecoinpressionv cylinders during Lthe working strokes; said pistonscompressing the air in the air compression cylinders on the workingstrokes; an exhaust por-t for exhausting the waste products ofcombustion from each working cylinder at the end of the working stroke;means for admitting compressed air into the working cylinders toscavenge and cool'same during the escapement of waste products ofcombustion from said working cylinder; said pistons compressing the fuel4vapors in the pre-compression cylinders during the return strokes;

means for shifting said valve to admit part of the compressed fuelvapors into the Working cylinder during part of the return stroke; andmeans for shifting said valve to direct the remaining part of saidcompressed l vapors forth in claim 3, each valve comprising a 'casingclosed at both ends;

a port in said casing adjacent its lower end communicating With saidcarburetor; aport in said casing adjacent its upper end communicatingWith said Working cylinder; said casing having an annular recess in itsWalls intermediate said ports and communicating with said valvecomprising` a rod said pre-compression cylinder; a tubular pistonreciprocably mounted yin said casing above said first port and havingits lovver end closed` and having'openings in its Walls adapted toregister with said annular recess; radially disposed vanes Within saidpiston for directing' the vapors towards the center of said piston; andsaid means for shifting on said piston actuated by the engine cam shaftfor shift-f ing said valve to establish communication between said lowerport and annular recess,

or between said upper port and annular recess. y

In testimony that I claim the foregoing as my oWnI affix my signature."

HENRY LOWE BROWNBACK.

